1. Field of the Invention
The present invention generally relates to an image forming apparatus, such as a printer, a copier, a facsimile, etc., and in particular relates to a toner replenishing device capable of replenishing a developing device with toner stored in a toner storage container.
2. Discussion of the Background
In known image forming apparatuses, such as printers, copiers, facsimiles, etc., a toner storage container such as a toner bottle or a toner cartridge is disposed within or in the vicinity of a unit which mounts a developing device. The developing device generally is replenished directly or via a toner hopper with toner conveyed from the toner storage container. In such a construction, conveyance of the toner from the toner storage container to the developing device generally is performed by a mechanical auger such as a screw, a paddle, etc.
However, when the mechanical auger conveys the toner, since the screw, for example, can only be arranged substantially straight, the toner storage container and the toner replenishing device are necessarily integrated with, or in the vicinity of, the developing device. Thus, the construction of the toner replenishing device is complex, costly and has low productivity and a low machine maintenance performance. In addition, protection and maintenance of toner quality characteristics are burdensome. In addition, it is generally difficult for a user to exchange a toner storage container.
Japanese Patent Application Laid Open No. 04-9082A has proposed a toner replenishing device capable of suppressing such problems. Specifically, the toner replenishing device conveys toner using suction generated by a suction device, and has an advantages that toner can be replenished, whatever positional relationship exists between a toner storage container and a developing device or the like.
However, toner utilized in an image forming apparatus which employs an electrophotographic system generally has greatly poor fluidity, and it is typically noted that conveyance of such toner is difficult. Accordingly, there are problems in the above noted toner replenishing device that toner clogging easily arises at a leading end or a middle portion of a suction pipe, and as a result, toner is not smoothly replenished.
Accordingly, it is an object of the present invention to address the above and other problems and provide a new image processing apparatus. The above and other objects are achieved according to the present invention by providing a novel toner replenishing device including a toner conveyance path extending from a toner storing device to a developing device, a toner conveying device for conveying toner from the toner storing device to the developing device along the toner conveyance path, and an air supplying device connected to the toner conveyance path via an air supply path for supplying the toner storing device with air from a bottom of the toner storing device so as to agitate the toner pooling in the toner storing device.
In yet another embodiment, the toner storing device includes an evacuation section at a top thereof so as to evacuate and receive air.
In yet another embodiment, the evacuation section is made of a breathable filter so as to efficiently evacuate the air.
In yet another embodiment, a multicolor image forming apparatus includes an air supply control device for controlling supplying of air to a plurality of toner storing devices and a fewer number of air generation sources than the plurality of toner storing devices so as to efficiently supply the air to the plurality of toner storing devices.
In yet another embodiment, the air supply control device controls both the driving of the air generation source and the opening and closing of a plurality of openable valves provided in a plurality of toner conveyance paths in such a manner that the plurality of toner storing devices is supplied with air one after another when the air generation sources are driven, so that an amount of air supplied to each of the toner storing devices can independently be supervised.
In yet another embodiment, the toner conveyance path is configured to receive at its middle portion user toner collected by a cleaning device so as to recycle the toner and protect the used toner from needless stress.